Traction means for vehicle wheels



Jan. r12, 1932. v H. A. JoHNsToN 1,840,779

TRACTION MEANS FOR VEHICLE WHEELS,

Filed June zo, 1928 2 sl'qeys-sheet 1 Y Jan- 12 1932 H. A. JOHNSTON i 840,779

TRACTICN MEANS FOR VEHICLE WHEELS Filed June 20, 1928 2 Sheets-Sheet 2 4 gj/522%@ /l j] 2126 f4 1 if, llalilllmll n @l l 44 2936 e4/0 @Z222 [2721/00 254A Z6 Y E v f Patented Jan. l2, 1932 UNITED 'STAIRS PATENT OFFICE I HARRY A. JOHNSTON, OF RiinLiANips, cALiFORNIA, AssICNOR TO JOHNSTON TRACTORS c y COMPANY, LTD., OF LOsANenLEs, CALIFORNIA, A CORPORATION or CALIFORNIA TRACTION VMFANS TOR VEHICLE WHEELS `.Application filed June 2l),

^ with rack teeth having openpspaces there- Y between which rengage a gear Onthe periphery of the wheel. The chain-like track is conveyed and guided byloosely mounted rotatable rings heldin place by flanges Yextending radially inwardly from theflinksof the chain.

Anotherobject of my invention is the arrangement whereby the rings havelarge central openings to accommodatethe eccentric movement of the rings relative ltothe hub of the gear wheel, the rings being inateriall larger in diameter than the wheel.' 1

Another object of my invent-ion is` mounting the gear wheel on a fixed axle so that the support of the vehicleis directly carried ,by this axle and the gear wheelfthrough the medium of the endless chain track, such track Y having pivotally mounted shoes to engage the groundfandfform an extended bearingsurface. 'And in this connection a detailed improvement is the constructionby which sub-y stantially three shoes are in engagement with the ground at the same time forming va broad supporting surface; and between" the shoes there are projecting grousersfconnected .to the endlesschaintrackengaging the ground and givingl increased traction orv `'effectively preventing slippage. Another object of myfinvention is a detailed'improvement in the formof teeth used onthe vendlesschai-ntype of rackand the supporting of the wheel Von running Vsurfaces of the endless chain so that no pressure other than the driving force is brought -to bear non' theV teeth. f f 1 giving a smooth and even 192s.' .serial No; 286,839.

v The teeth of the rack are graduated in size from a large tooth at thecenter of each ylink to asmall tooth atth'e end vor pivotal con: nection ofadjacent links; and between .these links there are Openings to allow the teeth of the supporting wheel Lto extend therethrough.I TheV carrying of the VWeight is through the medium of track-like surfaces on the individual links on which peripheralV surfaces on v.the supporting wheel run,fthus support at the ends of the teeth.,I n l Anotherv feature of my, invention `is in-the centering of the rings on the wheel byI means of the hub. engaging the openings infthe rings.V

Another feature relates to the'shoes scraping themud from the Vgrousers onthe chain. K

. My invention will be more readily understood-from the following 'description and. drawings, in which: c f

F ig. 1 is -a sidev elevation. of a traction means constructed in accordance with my invention,lpartly'broken away,`

Fig. 2 is a vertical section on the line '2V-2 of Fig. 1, l

Fig. 3 is a plan view of the portion of the endless chain and shoes in engagement with theofround as illustratedin Fig. 1, the wheels and rings being removed, f Fig. 4 is a plan of one ofthe links'of'the endless chain ytaken inthe direction ofthe arrow of Fig. r5, Y Fig. 5 is aside elevation of such linkA taken inthe direction ofthe arrow 5 of'Fig. 4, s

Fig. .6V isan end elevation of the same link taken i-nf the direction of the arrow 6 of c 5, v V "Figf is in the direction of thearrow 7 of Fig. 8, n

.Fig 8 Vis a side elevation of a shoe taken in the direction yof the arrow 8 of Fig. 7

arprlan of one of the shoes-taken Fig.v v9 is an .-end elevationof a shoe taken Cil the axle 11 having a wheel designated generally by the numeral 12 mounted thereon. This wheel has a hub 13 keyed or otherwise secured to the axle. Extending outwardly from the hub there is a webb 14 which at the outer portion has a peripheral channel-like structure 15 with llanges 16. Vlhe peripheral portions 17 of these flanges form bearing surfaces. Between the flanges are the shrouded gear'teeth 18. The various features of the wheel are preferably formed integral and the teeth may be of any suitable shape, but these will be noted extend to a considerable depth radially inwardly from the peripheral bearing surfaces 17. (Note particularly Figs. 1 and On each side of the wheel is a ring 19 having a large internal opening 20 with an internal rim 21 adjacent thereto and having an outer peripheral surface 22. The large opening is to accommodate the eccentric mov-ement of the' rings relative to the hub 13 and the axle 11, and the peripheral surface 22 is adapted to bear on a track surface of the endless chain as hereunder set forth. (Note particularly Figs. 1 and 2.) l

VThe endless chain is designated generally by the numeral 23, the general construction being shown in Figs. 1 and 2 and the particular details in Figs. 3 through (3. Flach link of the chain is constructed with side rail sections 24 connected at one end by a knuckle structure 25 and having at the other end a pair Vof ears 26.

The knuckle structure and the ears have perforations therethrough through which pass theV chain pins 27, these being illustrated as secured by cotter pins 28.

Connecting the side rails are the teeth 29 with openings 30 therebetween. Outside the side rails are inwardly extending flanges 31, which it will be noted are substantially triangular shaped in side elevation, the base portion of the triangle terminating inside of the chain pins 27'. Extending below the center tooth is a transverse grouser 32 and eX- tending outwardly from the side rails outside of the flanges 31 is a lateral projection This projection in plan view is somewhat triangular shaped as shown in Fig. 4.

lt will be noted that there is a cut away portion 34 on the under side of earth of the links as viewed in side elevation, particularly illustrated in Figs. 1 and 5. This lightens the construction of the individual chain links. It will be noted that the center tooth 35 is longer'than thetwo teeth 36 adjacent thereto, and that there is a rudimentary tooth section 37 formed, utilizing the structure of the hub 25. However, this rudimentary tooth has its upper' end at substantially the level of the top surface 33 of the side rails.'

The shoes designated generally by the nun meral 39 are illustrated particularly in Figs.. 1, 2, 3, 7, 8 and 9. Each shoe is provided with a tread or plate portion 40 curled up at opposite ends as indicated at 41 and having lugs 42 on opposite sides. These lugs have perforations 43 through which extend the pins 27, thus linking the shoes to the pivoting point of the links of the chain. The shoes have fins 44 on the upper surface extending from the lugs to the curled up ends 41.

Below the under surface of the shoes there are longitudinal grouser teeth 45. The lower surface of these grouser teeth are designed to extend the saine distance from the top rail surface 38 of the side rails 24 as the lowermost edge of the grouser teeth 32 of the chain links.

The manner of operation and functioning of my traction means is substantially as follows: ltis to be understood that the axle 11 may be driven or may be a dead axle. ln the former case the traction device may be used for hauling a load, or in the latter case may be given increased support on the ground for the load to betransported. The weight of the vehicle is supported on the wheel 12, the peripheral edges 17 of which ride on the track surfaces 38 of the side rails 24. rl `he shrouded teeth 18 engage the teeth of the links of the endless chain which links in effect form a rack through themedium of the shoes which are adjacent the ground. In rotation there are always two or three shoes in en gagement with the ground, and when the weight is supported centrally over. one shoe there are three shoes on the ground; and when the weight is on the middle of a link there are two shoes on the ground, giving an even distribution of weight.

The peripheral edges 22 of the rings 19 also ride on the track surface 38 of the side rails 24, and thes openings 20 in these rings are of sufiicient diameter so that there is always a clearance between the lowermost part of the hub 13 and the rims 21 of the rings adjacent thereto, this being illustrated in Fig. 2. The rings are held in place by the triangular flanges 31 extending inwardly from the links of the endless chain.

.In the movement of the vehicle either through the driving axle 11 or Vby otherwise moving the vehicle, the shoes are brought into engagement with the ground, the links of the chainconnecting the shoes which engage the ground being straightened out into a more or less straight rack formation so that the shrouded teeth on the wheel engage the teeth of the links, the teeth of the wheel passing through the openings 30 of the links. The chain has a somewhat loose fit on the rings 19 (but for the major portion of their movement when not in Contact with the ground the track surface 38 of the side rails of the links is in contact with the peripheral rings 22 of the discs, as illustrated in Fig. 1. lt will be seen on account of the engagement of the large grousers 32 of the chain links with Vthe lground anda'lso of thezgrousersft' of the shoes that ,I yobtain-'a good traction on soft soil; and moreover the grousers82 of thel An important featurefof my invention isthe manner in which the rings maintain the chain and hence the shoes at the proper dis tance from the hub. There is a slight clearance between the periphery yof the hub 13 andthe inner surface 20 ofthe opening in the. rings so that inrtlie correct position vof ruiming there is no contact between the hub and this surface..V However, if therings tend t0 roll too far forward or backwardly, then'the surface 20 willcontact with the 'hub preventingan excess motion Vin this regard. The chain is preventedfrom coming in contact with the gear wheel except at the bottom and there is no danger of the teeth ofthe gear andthe chain accidentlyintermeshing on any partof the rotation above the bottom portion ofthewheel. l .Another Ycharacteristic of my invention'is that the gear wheel runs on pthe ,pitchA line` of the teeth and the track on the chain is. on the pitch line of the.. teeth of the chain.

Anotherifeature of myV invention is .that thegrousers 32are kept clear of clinging mud asin the rotation ofthe f' chain when; thesegrousers are elevated-fromthe ground they substantially scrape against .the curled up ends 41 of the plate of the shoes.' n n A further feature of my'inventionisthat the-rings which form a guiding means for the endless chain track are' practicallyalways substantially centered on the Vnormal toet-he ground surface so that on a horizontal suri face the center line4 of the rings is practically inY the sameplane vas the center liner ofthe axle, and on a gradefvvith the line through the center4 of the axleeand'thecenterof the rings is normal to thegrade.vv

l,A function performed by the shoesl and thev grousers is that the Vshoes tendto keep 4the grousers 32 clearvof Vaccumulation of dirt-.- Referring to Fig. 1,it;will be noted that the ends of the shoes are in `close Vproximity to the grousers and, hence', in theA tilting action of the shoes inleaving the ground these have a scraping action, removing the dirt from theA grousers and thus maintaining thegrousers Various changes'maybe made-in the p'rin-Y thereon having shroudedteethiperiph` eralbearing surfaces, an endless track .formed of pivotally connected links, each link having sideirails connected by transverse teeth, the

peripheralbearing surfaces of the wheel running ion thev said rails, a .pair of rings each having a peripheral edge running'on the said rails and forming. a guide forthe portion of the linksdisengaged from the ground, out of contact with the wheel, the rings having openings of such size as to space the lowest the lowest por-;`

portion of the openings from tion of the'axle. v

2. A traction means comprising in combination a rotatable wheel, an endless track formed ofpivotally connected chain links, the peripheral portion of the wheel'running ontheinner surface of the links, a` ring adjacent thegwheel running on the inside of the links and forming a guide for the portion of the links disengaged from the gro-und out of Contact with thewheel, shoes pivotally connected toA the links at their pivotalv connections to each other, and a ground engaging structure connected to each link alidoextending outwardly between two adjacent shoes.

like, endless track encircling said wheel and having meansv to engage the ground, the wheel running on the said ltrack and a guide structure extending beyondl the periphery of l the wheel and rotating eccentrically thereto and rotatable with the track and .running on the trackto guide the portion of the track disengaged Afrom' theV ground,'out of. contact with the wheel. i k5. AV traction means comprising in combination a supporting wheel running ontlie inner side of an endless, chain-like, flexible' track encircling said wheel, the track having nieansto engagethe ground, a plurality of rings extendingbeyond the periphery ofthe wheel.v and rotating eccentrically thereto and on opposite faces of the wheel adapted to run onrtheinnersurface of the track, the

periphery ofthe rings forming a guide surf face for the .portion of the track disengaged from the ground and'guiding such portion of the track out of contact with the'wheel.y

6. A traction means'compiising combi- Vnation-an axlehaving agsupporting wheel mounted thereon, said wheel running on the innersurfacefof aflexible, chain-like, lendless; track encircling said wheel, thetrack of rings extending'beyond the periphery of the .wheel ,and rotating eccentrically thereto having means to engageitherground,a .pair

and on opposite faces'of the wheel running on l the inner surface of the track, they peripher of th-e rings guidingY the portion-of thetrack disengaged from .f the; ground,` out of contact with the wheel, and means on kthe track to retain the'rings in position.

7. A traction means comprising in combination rotatable wheel, an endless chain track having side rails encircling the wheel,

the track having means to engage the ground,

tne wheel having a peripheral portion running on the said rails with interengaging means between the rails and the wheel to form a drive, and a supporting structure extending beyond 'the periphery of the wheel and rotating eccentrically theretoadjacent the wheel and associated therewith running on the said side rails, the supporting means forming a guide for the portion of the track disengaged from the ground and guiding said portion of the track out of Contact with the wheel, the said supporting means rotating with the track. i

8. A traction means comprising in combination aA rotatable supporting wheel having a peripheral surface to run on side rails of an endless chain track encircling the wheel, teeth on the wheel engaging with teeth on the links of the chain, guide rings extending beyond the periphery of the wheel and rotating eccentrically thereto and positioned adj acent the wheel having their peripheral edges ruiming' on the side rails, the said rings forming a guide for the portion of the linksof the chain disengaged from the ground, out of Contact with the wheel. i

9. A traction means as claimed in claim S, the links having inwardly extending ianges engaging the said rings on the outside and retaining said rings in position.

10. A traction means as claimed in claim 8, the links of the chain having openings between the teeth to `allow projection of the teeth on the wheel therein, and the teeth on the links being of diiierent lengths.

11. A traction means comprising in combination a rotatable supporting wheel having shrouded teeth with a peripheral bearing portion, an endless track formed of pivotally connected chain links having side rails, the said peripheral portion of the wheel running on said rails, a pair of rings on opposite faces of the wheel and extending beyond the periphery ot such wheel and rotating eccentrically thereto, each having a peripheral edge ruiming on the side rails and forming a guide for the links, and shoes pivot-ally connected to the links at their pivotal connection.

12. A traction means comprising in combination a rotatable supporting wheel hav-l ing shrouded teeth with a peripheral bearing portion, an endless track formed of pivotally connected chain links having side rails, the said peripheral portion of the wheel running on said rails,v a pair of rings each having a peripheral edge running on the side rails and forming a guide for the links, and shoes pivotally connected to the links at their pivotal connection, thel links having inwardly eX- tending flanges engaging the rings and retaining same in position, and each link having an outwardly extending grouser fitting between two adjacent shoes.

13. A traction means comprising a supporting wheel running on the inner side of an encircling, endless, flexible track, the track having means to engage the ground, guide means adjacent a side face of the wheel and extending beyond the periphery of the wheel and rotating eccentrically to the wheel engaging the inner side of the flexible track by a. sliding engagement to guide the portion of the track disengaged from the ground, out of contact with the wheel, and mea-ns to retain the guiding means in a substantially constant guiding position relative to the wheel.

14. A traction means comprising a sup porting wheel running on the inner side of an encircling, endless, flexible track, the track having means to engage the ground, guide means adjacent a side face of the wheel and extending beyond the periphery of the wheel and rotating eccentrically to the wheel engaging the inner side of the flexible track by a sliding engagement to guide the portion of the track disengaged from the ground, out of contact with the wheel, and means to rotate the guiding means in a. plane parallel to that of the wheel.

15. In a traction means, an endless track formed of pivotally connected chain links, each link having opposite side rails with a flat bearing surface, teeth connecting said side rails, there being spaces between the teeth, the teeth of each link being of different elevations in regard to the bearing surface of the side rails, the center teeth being materially longer than'the teeth at the end of each link, the teeth at the end of each link being formed adjacent the pivot forming the connection to an adjacent link, and a load carrying wheel rolling on said rails and having teeth engaging the teeth of the links, the teeth on the wheel extending into the spaces between the teeth on the links.

16. In a traction means, a load supporting wheel having teeth of approximately the same length, an endless track formed of pivotally connected chain links passing over said wheel, said wheel running on said links, each link having teeth to engage the teeth of the wheel, the tooth at the centerA of each link being materially longer than the tooth at the pivotal end of the link, and the intermediate teeth being graduated in length, thereby providing a clearance for the teeth on the link in leaving and entering the teeth on the wheel in the rotation of the wheel. y

17. In a traction means, a load supporting wheel having shrouded teeth and being provided with a peripheral rolling surface, an

endless track formed of pivotally connected chain links, each link having tracks engaged by the periphery of the wheel, a guide means r-otating eecentrieally with the Wheel and formingl a guide for the e'hain links which are diseonnected'from the ground, each link having teeth, the center tooth of each link being Y materially longer than the ltooth adjacent the pivotal end of the link, and the intermediate teeth being graduated in length between the name to this specification.

I-I. A. JOHNSTON. 

